Is BMI Accurate?

Body mass index (BMI) is used to determine whether you are at a healthy weight. It’s a very simple formula that uses just two variables – height and weight. Can you really get a good measurement of health from BMI?

Is BMI Accurate?

Let’s take a look at the BMI chart above. Look closely at the section highlighted in yellow. If you fall into this section, you are considered overweight.

Now, do you think that a 5’6″ male that works out, and is 181 pounds at 8% body fat is overweight? I don’t, but according to this chart, that person wouldn’t just be considered overweight, he would be borderline obese. You tell me, does this person look like he’s almost obese?

Does Kendrick Farris look overweight or even close to obese?

What about a 5’8″ female that is 158 pounds? According to the BMI chart – just 3 pounds away from being overweight. Does the person below look 3 pounds away from being overweight? Do you see the pattern? For people living an active and fit lifestyle, BMI is close to worthless.

Does Shannon look close to being overweight?

I’ve heard countless stories like this from other people too. Doctors telling their patients they need to lose weight because this arbitrary BMI chart says they’re overweight.

When are we going to move beyond such a ridiculous measurement? The body mass index (BMI) was created during the 1800s. Have we not advanced enough as a society to figure out how meaningless this measurement really is?

Is BMI Accurate? NO. Then What Is?

Thankfully, there’s no need to reinvent the wheel. We already know how to take accurate body composition readings. Body fat measurements tell the bigger story. We even have tests now to show how much fat mass, muscle mass, and other mass our bodies are comprised of.

Let’s Start Rethinking Weight Measurements

What if someone starts a weight loss program weighing 200lbs. What if after a month this person still weighs 200lbs. Would you say they made any progress? The answer is we have no idea if the only progress measurement tools we use are the scale and BMI.

Not only could you have lost more fat than the scale is showing, but you could have also put on some muscle. Can your weight show you that progress? Nope. Can the BMI show you that? Not a chance. Is the BMI accurate? Only as an average of the population at whole. For people living a fit lifestyle, it’s time to retire the BMI for good. Focus your efforts on changing your body composition.

Calculate your BMI from the chart. Is it accurate? Does it represent a good portrayal of your body composition?

52 Comments

Tony Schober

Hey Everyone,

Just wanted to let you know that if you need more help losing weight you can download my ebook The 10 Forgotten Rules of Weight Loss absolutely free.

So glad you posted this article. I am currently on a weight loss journey having lost almost 70 pounds so far. When I first started, I looked at my BMI and was very discouraged. Several weeks later as I was getting into more specifics, i.e. fat mass versus lean mass, I figured out that BMI was bunk. What is most disturbing to me is that medical professionals so readily accept this as a measurement of health as a standard, which is mind blowing. Specifically the surgical weight loss practices use this as a measurement to determine if individuals qualify for weight loss surgery. I would venture to guess that the majority of health care professionals have no idea where the measurement comes from or when it was put into practice. As you said, in the 1800s. Furthermore, it was not created by a health care professional, but a mathmetician! I am so glad that you are educating people on this issue. I love your daily articles. They help me to stay focused on the task at hand and question whether I am on the right track.

Unfortunately, it’s going to take some time before we readily move to body composition as a measurement of health. The chart is just too easy and quick to use to be replaced anytime soon. Slowly but surely…

Well done Mary on your weight loss, I too have lost 70lb through exercise and healthy eating, this has left me at 48 with an apron of skin that is hanging and saggy and makes me cry every time I look in the mirror. I know that no matter what i do or how much more weight i loose (and i still have a bit to go) this will not look any better. I have turned my life around and become a Personal Trainer, but this flabby tummy of mine is affecting my confidence, why should my clients listen to what i tell them while I have this bulging baggy belly.
I went to the doctor to request he refer me for surgery to have it removed but my BMI was 31 and he said I have to get it below 30 to QUALIFY for referral. This has disheartened me with all the lifestyle changes I have made by myself with no help from the medical profession.
I wonder what I would have to take it UP to so that i could qualify for Barriatric Surgery to help me get my BMI below 30 so I could qualify for a Tummy Tuck.
Now that is a thought, I think i may pay my Doctor another visit and tell him this is what i am considering doing just so i can get rid of my loose skin………..watch this space.!!!!!!

The BMI chart you posted is labeled wrong! BMI 18 or under is underweight, the green is the Healthy Weight, a BMI 25 or over is Overweight, and BMI of 30 or more is Obese. I agree that the BMI for men isn’t accurate if muscular, but for women the BMI gives a wide range for Healthy Weight, even if muscular. People should look more at body fat percentage and waist size. For women a waist over 35 is dangerous and for men over 40, plus it’s a sign of possible metabolic syndrome or diabetes. People with a large waist usually also have high triglycerides, low HDL and high BP, so they should be checked for diabetes.

Hi Sharon, what you posted is what the chart says. Take a look at the “chart key” at the top. It’s a bit confusing because the label “underweight, healthy, overweight, etc” is above a different column, but it’s next to the correct color to the left that it’s labeling.

im so glad you put that up im according to bmi index im overweight im 5ft and weigh 9st 4lbs im just a tidge over what i left school i couldnt be any thinner id be ill as id have to be anorexic to be the weight they said wait for it 7st 2 to 7st 9 never in a month of sundays no wonder girls are dieting the way they are im 49 years old i exercise everyday cos i love it and i eat really healthy so i told them to stick there bmi up where the sun dont shine trishxxx

Thank god finally someone with some sense. I am classed as on the line between obese and dangerous according to doctors the only thing is i am only a size 14. Yes i am over weight for my height but not massively. I do weight lifting aswell but they don’t take that in to account. I just need to lean out the fatty bits. Its the same with my son he got his first school health check at the age of 5 and I got a letter to say that hes over weight and needs to diet. OMG he is the tallest in his class infact he is the same height as the 8 year olds at his school and hes now way fat in the least so I tore up the letter as i feel all this BMI stuff is alot of rubbish and could possibly damage alot of people physically and mentally trying to keep doctors happy. “Eat healthy and excersice regularly and you wont have a problem with weight” thats what doctors should be saying.

For people that exercise, BMI will always skew the readings to the right of the chart (more towards obese). It can be a useful guide for people who live a sedentary lifestyle, but for fitness minded people, body fat percentage is the better indicator.

Jennifer, head over to Amazon.com and do a search for body fat calipers. You will find that they range from under $10 for a plastic pair to over $100 for a nice pair. One might end up being more reliable than the other, but it’s the relative change from measurement to measurement that’s equally important.

I have lost 75lbs over the past 3.5yrs. I was seriously overweight at 215lbs, 43% BF… I am now 5′ 6″ and 140lbs, 19% BF. Most of society would think that 140lbs is too heavy. It is sad that we live in a world that we are programmed to only concentrate on the numbers. I am leaner than I’ve ever been in my life, stronger than I could ever thought I could be… I wear a size 2/3 jeans, xs in athletic wear, etc…. Hopefully someday the medical field will open their minds and eyes to the fact that no two people weighing the same but with different body compositions will look the same. I am the same height and weight as my mother but she doesn’t workout like I do… she looks as if she was a good 15lbs heavier than I. Also she wears a size 8 vs my size 3. I definitely agree with the “fit is the new skinny” mentality. Fit is sexy. Congrats and Kudos to all that have traveled the fitness/weight-loss path. I too having had 4 kids and riding the weight gain/loss rollercoaster, sport a patch of skin on my belly that will not firm up for the life of me. I am also a PT. My clients are relieved I understand the struggles, misconceptions, joys, pains of weightloss.

I was thinking of getting a pair of calipers… i presume it matters where you measure? Fore instance if i measure my thigh it will show less than my tummy? Like Julie i too have flabby belly after having 3 large babies but at 45yrs old now and running 4klm every 2nd day plus weight training i find only the tummy area disappointing(stretched and excess skin).

1 – to measure the relative change in skin-fold measurements from a particular site (ie thigh, butt, triceps, etc)
2 – to measure your body fat percentage (you will have to measure at particular places for this)

For #2, google “body fat skin-fold sites”, and there should be plenty of diagrams of where you should measure. Once you have those measurements, you can put them into a calculator and get your BF%

I have always been considered overweight according to bmi charts. I’m 5’1 1/2″ and I have a muscular frame. Growing up I felt I was fat because that’s what I heard-although I wasn’t fat at all, not even overweight. I have always been an athletic person. Even now, at 43, having had a baby by C-section 6 months ago, I exercise regularly, play co-ed softball, and take advantage of outdoor activities. Granted, I do have some baby fat to lose, but when I calculated my BMI I was so discouraged to be in the obese range, and this was before I became pregnant with baby number 3! These charts never take into account a person’s muscle mass or body frame. Muscle weighs more than fat. I’ve had people tell me-who are considerably overweight-their weight and I outweigh them by 20 pounds or more. All my life I have felt extremely fat, even when I was at a healthy weight because the “chart” said I was. It’s great to read articles such as these. It would have been even better if I could have read something like this when I was a teenager because it might have helped with my low self-esteem with my body image that has stayed with me! Thank-you!!

Well said Cindi A. I have had the same thoughts on my weight loss journey over the past year….I wish I had know this information as a teenager. But the blessing is that you DO know now and we can both help our children have positive body images as they grow up.

I agree the above chart can be quite out of whack…but in my case it’s spot on at the moment.
I also think the waist to hip ratio method of measuring body fat can be wrong…I think it should be waist to height ratio…makes more sense to me. Oblong people are slimmer looking than square people..lol

Our school district sends a letter home each year with each student. It lists height and weight of the student with a BMI chart listing which BMI’s are underweight, normal, overweight, obese etc. With the increase in disordered eating and poor body image in the teenage population, this could be devastating to certain students. Of course testing body fat for each student would take too long and would probably upset some parents and students, but it would certainly paint a more accurate picture.

As a fitness professional I have always struggled with BMI. Working in a corporate setting where people are hesitant to have their BF taken, it remains the fall back tool. I dislike it so much that I work hard on building a relationship with the individuals so they feel comfortable enough and trust me to take their body fat. I am continually telling the story of a friend of mine who has completed TWO Ironman triathlons and according the BMI chart he is obese. That is ridiculous. I also hear a lot of people say – I am big boned. As a results I have found charts that indicate frame size based on wrist and elbow measurements. I hate to burst bubbles but if changes are to be bad, expectations must be realistic and people need to understand where they are really starting from. The journey is about healthy eating, exercise, hydration, being real with yourself, and having lots of patience. Thanks so much!

For the past three years I was under a huge amount of emotional stress due to a now ex who assisted in my now hormonal imbalance, adrenal fatigue leading to hypothyroid which caused me to gain an excessive amount of weight due to all the stress and abuse I endured

I have always been very healthy w/ great endurance;however, this past ordeal as well as age took a toll on me but once I stopped listening to others and went back to my own confidence my situation has changed in a positive way; however, the BMI chart (and to my point) has completely messed with my head.

Now don’t get me wrong I have a lot of work to do to get back to where I feel my best but by no means do I look obese and according to the chart I am 2lbs away from being obese now it states I am overweight and yes I could lose a great deal of weight but my body for the most part is hour-glass figure except a little apple belly now ;( & puffy face and I wear a size 12/L so does this really make me close to obese – in my head it does

Anyway my confidence is back which helps but I am still not 100 percent so any advice or constructive critism would be welcomed but did want to thank you for this article as it helped me to put this away as I decided to do what I know was always best instead of listening to people telling me to stop eating – that is the WORST thing anyone can do. I rarely eat bad I just put the fork down like an idiot told me to bring me down because of his own insecurities when I was secure prior GRRR but new fresh start ;D

Anorexics are another example of the BMI myth…according to the BMI charts, people with this disorder are underweight HOWEVER if a measurement is taken to compare lean vs fat mass they are considered to be overfat given that the body will consume it’s muscle mass first during periods of starvation.

I am so happy to hear of the change, it is so important people learn this because either end of the scale we get wrong answers. I don’t believe it is any better for women than men however as said in 1 reply. I also would like to add that 1kg of muscle and 1kg of fat is the same, we need to abolish the notion that muscle weights more than fat because no matter how we want to look at it a kilo is a kilo. Yes the mass of each is much different in size! Too many people live with this false notion in their lives believing that 1kg of muscle weights more. Well done to you all who are and have achieved awesome fitness goals, I too am on a journey of health and fitness and plan to enjoy this life long journey with the hopes of becoming a trainer in some form. My PT Ryan is a great inspiration too me! Also thank you coach calorie for this site…Jo

Finally!!! I had been privy to this information for a very long time as I have always carried an active lifestyle…perhaps, not quite as fit as these athletes, but, I stay fit on the regular with my routines of cylcing, hiking and going to the gym….Thank you for enlightening the rest of the folks out there!

The BMI is a crock! I’ve always been muscular – my legs especially – When i got pregnant, I gained a lot of weight. However, in the past year, I’ve dropped 100+ plus where i was grotesquely obese at 259. I am now 151, feeling much better and more muscular than ever. In fact, I am wearing sizes less than I was before I got pregnant 19 years ago.

Although I am 151 pounds, I look much better and skinnier than I did when I was 18.. However, I’m short at just 5’1″ tall… And, according to the BMI, I am near obese… According to that stupid thing, I should weigh around 115 pounds.. I never weighed that even BEFORE I had kids.. My goal is 130.. which is 10 pounds lighter than when I got pregnant those so many years ago.

I do a lot of weight lifting so my arms and my legs are very muscular. My body frame is that of a man. I can out-bench, lift and run many men that I know.. But, i’m still near obese according to that stupid chart!

And, my kids.. let’s not even get started… Those letters being sent home are just one step closer to more kids with eating disorders. And, the fact that insurance companies use it to charge people more money for being “overweight or obese” just pisses me off too!

I love your articles Tony and I am learning a lot. I lost 27 lbs. since June which is a slow but healthy rate. I have about 30 lbs. more to go but I am more focused on the body fat% as per your articles. Only thing is that I fear that am losing muscle. Are those body calipers that you suggest good for people who have 30 lbs. to lose? I am now measuring my belly to see if that goes down at least since it’s also a health risk. Also, do you think that kettlebell workouts are good for weight loss and toning? I am doing that 2x a week for 30 min. in a very intense class that intervals throughout the class and I think I am getting thinner but not more toned. I do eat whole foods, grass fed meats, poultry, nuts, avocado/healthy fats, a green smoothie, really pretty good – not perfect but very good.

I think they are good to measure relative difference in skinfold measurements. They obviously won’t be the most accurate, but for the price they can’t be beat. I personally use the Lange calipers, but they are much more expensive.

Kettlebell workouts are fine as long as you can add enough resistance and keep the intensity high. Anything that you enjoy and can push yourself with is a good choice.

Thank you! Those Lange ones look nice but for now I will have to stick with ordering the economical calipers that you suggest in your articles. I do enjoy the kettlebell workouts and they are taught by a martial arts instructor who keeps it pretty intense – I sweat out of my palms! I think though that I am ready to up the weight at least for the swings. After a few months of this I may keep these two classes or do 1 class and add in some of the weight training that you talk about in your articles. Love your articles, thanks for sharing all the great information!

Bmi is fairly accurate for me.. i have an apple body shape.. … I worry about BMI and waist size mostly… when i get my waist under 32.. i am a “ruler shape”.. but… Even when i was a size 5.. i was “fat” skinny.. those fat percentage scales called me obese.. :))

Such an emotional topic!
Just scanning through the responses below, most people responding have higher than average muscle mass, which sorry to tell you, is not what the vast majority of the population is. The people in the images above are not just ‘living a fit and healthy lifestyle’…..they do it to win, to compete. And, as you pointed out in the article, the crossfit lady (who could probably belt out 10 chin ups for every one that I can do) is still in the healthy weight range, despite being a crossfit-type competitor.
We know that you can’t use this measure for athletes or people with high muscle mass, that’s old news, so stop making this so emotive!

As soon as my clients, who are ordinary people – not athletes or ex-body builders start to move towards the mid 20s in the BMI index (through resistance, cardio and diet) , they start to look good, they have muscle tone, their clothes look good on them, they’re ‘healthy and fit’.
I think the BMI index is a great tool because its SIMPLE. It’s not so invasive, you can do it at home by yourself. Sure, its not perfect, but neither are many other tools that we use such as max. heart rate indicators, blood pressure testing or most fitness tests.
They are just indicators, people. And if your BMI is showing 40 and you think you’re OK …well….think again.

You make some interesting points. However, it is still inaccurate for people living a fit lifestyle. The crosscut girl is very lean. Had she carried a little more body fat like a “normal” person, she’d be considered overweight.

I’m glad you wrote this article. I workout 4 days a WK, Im sure I’ve lost weight because the clothes n trousers that were snug on me two months ago, r so loose now, but my bmi means I’m overweight. I wear an 8 to 10 now and I’m 5″ 7″. How is that possible.

BMI is a cruel joke. I am 5’3 and have a muscular build. I have never been in what BMI considers healthy weight. I have been very athletic my whole life and continue to be. However from about age 12 until 24 I battled anorexia and would only allow my self to eat 500 calories a day and worked out upwards of three hours a day. I know that a big part of this was the BMI chart that always mocked me saying hey fat girl! Even though I was a size 2 (still overweight by this chart) I felt fat!

I lift and work out. I’m definitely overweight (by bmi I’m obese) at 5’2″ and in the 190s, but I’ve lost 2 pant/dress sizes in the last couple months and actually gained a couple pounds. My BMI is staying steady or worsening, but I’m healthier by any real measures (percent body fat and waist/hip ratio).

According to the BMI chart I’m one point away from being overweight. I’m not sure how many pounds that amounts to. Not very many I presume. Anyway I don’t think the chart is correct. I fit into t-shirts and shirts from the children’s department! I don’t mean junior, I mean the younger kids. The T-shirt i just bought was boys size 10-12. But I’m 45! So if I gain a few pounds I doubt if I’d be overweight.

I wear a M in pants. I like sleepwear to be looser so I usually wear large for that but the waistband needs to have ties on it I can tie.

My feet have shrunk and gone down to an AA in width. It’s a real problem. I walk a lot, at least 3 miles a day, so I need shoes that fit my feet correct. Yet most shoes pop right off of my heels. It seems that hardly anyone carries narrow shoes these days, probably because so many people these days are overweight or obese. I can visit every shoe store in a mall and come out empty handed, with not one shoe fitting correctly. Luckily I found a pair of girls Sketchers that fit my feet with double socks. Unsure what I’ll do in summer. I don’t want to wear double socks then. Just want people to know that when you lose weight your feet can shrink in width. A lot of people don’t know that.

I have a major food allergy so that’s one reason I’m losing weight. I have to avoid preprocessed food. Had to cut out all grains except quinoa and all nuts except pistachios due to cross contamination and shared equipment. Of course I’m active, do a lot of walking and body weight exercises.

Still have a little flab on my lower stomach I’d like to get rid of. Been working on that since Feb.

Years ago I was a bit over 200 pounds and wore an XWide shoe and XL t-shirts. I know 3 years ago I was around 159. Think I had stalled at that weight for awhile and then lost more.

The hardest thing about the weight loss is not the diet or the exercises. I feel good! It’s finding winter boots!! Nothing seems to fit my feet. My heel moves in virtually everything I try on. I found one pair that sort of fit and the left boot was dead in two months, the heel structure failing due to my more narrow foot moving in the morning when I leave the house. And I need boots in Dec and Jan due to the weather here: snow and subzero wind chills!

I want to add something as I was thinking. If the BMI chart says I’m almost overweight at 24 BMI but I fit into a boys T-shirt size 10 12 then what size of T-shirt do they expect an adult female to wear? It’s kind of ridiculous if you think about it.

Also exactly when is a person considered an “athlete”? To me an athlete is someone who plays sports. I don’t play sports. In fact I don’t like sports. But I do a lot of walking. I can walk a half marathon easily…but I don’t actually do marathons. But I like to walk to places. Or I like walking on the trail by the lake as it’s pretty.

So they say that BMI does not work on athletes. But who exactly is an athlete? Do you have an answer? Am I an athlete even though in my view point I don’t do sports?

I heard that BVI might be replacing BMI around 2020. Have you heard about that?